Here is a picture of the Kemmer BA-5 laser which is no longer in production. The laser follows the geometry of the gun much better. If you look closely, this is an older model of the P99 before Smith and Wesson began importing Walther firearms. The slide is slightly different as well as the rails.

Smith & Wesson has never taken over Walther Firearms. They are the importer for Walther Firearms. I have the first generation P99 .40 and have'nt been able to locate a tac light that will fit the first generation P99's proprietary rail. Umarex use to make a rail adaptor for the first generation, but its long been discontinued. The Streamlight TLR-2 tac light/laser will fit the 2nd generation P99 (2004 and newer) if you use the S&W insert that comes with the light.